Lift Bag Usage

[Zerovis]

if you are unsure of th tensile strenght of a rope test it on land first 13mm polypropeline rope is a good bet and practice your knots first the bowline is my favorite, or use a shackle if you have one

 

[pants!]

if you are unsure of th tensile strenght of a rope test it on land first 13mm polypropeline rope is a good bet and practice your knots first the bowline is my favorite, or use a shackle if you have one

13mm is huge. Rock climbers use rope (admittedly, it's kernmantle) that's as small as 9mm.

 

[greg1]

If you'll just e-mail the GPS coordinates to me, I have a buddy who will be happy to bring it up for you. He'll even e-mail a photo of it to you after.

theskull

That's funny s**t!!!!

 

[theskull]

That's funny s**t!!!!

So glad you enjoyed.

We had a pretty good thing going 'til NWG messed it up by actually giving good advice and facts. He's gonna put some instructors out of work that way.

Great description, Bob. You rule!

theskull

 

[Web Monkey]

Ok so lets say I find a 40lb porthole that I want to lift to the surface with my lift bag. What rope/line should I use and what would be proper technique?

Get a boat, a good captain, a long rope, another diver, a boat hand, and two lift bags each good for about double the weight of the object.

Tie loops in the rope it every 10 - 15 feet or so.

Have the boat hand hold one end of the rope so the boat and the object don't go their seperate ways if there's a current. Don't tie it off to the boat. If Something Bad happens, you want to be able to let go.

You and your buddy go down to the object and SECURELY attach the other end of the rope.

You and your buddy ascend to the topmost loop (somewhere around 10 feet), attach a lift bag and inflate.

Both the lift bag and object will come up about 10 feet, however because that's as far as the lift bag can go (between 10 feet and the surface), you won't have a runaway object, and everyting is still under control.

Leave the liftbag inflated, take the second bag down, attach to the next loop and inflate.

Once it surfaces, have your buddy deflate the first bag and send it back down, then you attach to the next loop, and inflate.

Keep doing this until the object is at the surface.

This is a great method, because:

• You never move the object more than 10 or 15 feet
• You're never under the object, so if it gets loose and falls, it won't kill you.
• There's no chance of having your object uncontrollably hurtling towards the surface, since each time you're only bringing it up another 10 feet.
• It eliminates a lot of work at depth.
• You only need to go down to the object for as long as it takes to attach the rope. After that, everything else is done in shallow water

I wish I could take credit for staged lifting, but I actually learned it from Gary at National Aquatic Service in Syracuse in a great Search and Recovery class. If you're in the area, it's well worth taking.

As others have mentioned, you want to do this first with someone who has done it before, since there are a lot of details to look out for (properly securing the object, estimating weight, checking how deeply it's embedded in the bottom, making sure the area is clear and everybody is away from the lines, etc.).

Terry

 

[ScubaSixString]

Ok so lets say I find a 40lb porthole that I want to lift to the surface with my lift bag. What rope/line should I use and what would be proper technique?

Couldn't you just clip it off to a plastic d ring on your bc vest? That way it won't get away from you





*ducks*
just kidding

 

[Hoosier]

This is exactly taught in the scientific diving class. Good description!

Get a boat, a good captain, a long rope, another diver, a boat hand, and two lift bags each good for about double the weight of the object.

Tie loops in the rope it every 10 - 15 feet or so.

Have the boat hand hold one end of the rope so the boat and the object don't go their seperate ways if there's a current. Don't tie it off to the boat. If Something Bad happens, you want to be able to let go.

You and your buddy go down to the object and SECURELY attach the other end of the rope.

You and your buddy ascend to the topmost loop (somewhere around 10 feet), attach a lift bag and inflate.

Both the lift bag and object will come up about 10 feet, however because that's as far as the lift bag can go (between 10 feet and the surface), you won't have a runaway object, and everyting is still under control.

Leave the liftbag inflated, take the second bag down, attach to the next loop and inflate.

Once it surfaces, have your buddy deflate the first bag and send it back down, then you attach to the next loop, and inflate.

Keep doing this until the object is at the surface.

This is a great method, because:

• You never move the object more than 10 or 15 feet
• You're never under the object, so if it gets loose and falls, it won't kill you.
• There's no chance of having your object uncontrollably hurtling towards the surface, since each time you're only bringing it up another 10 feet.
• It eliminates a lot of work at depth.
• You only need to go down to the object for as long as it takes to attach the rope. After that, everything else is done in shallow water

I wish I could take credit for staged lifting, but I actually learned it from Gary at National Aquatic Service in Syracuse in a great Search and Recovery class. If you're in the area, it's well worth taking.

As others have mentioned, you want to do this first with someone who has done it before, since there are a lot of details to look out for (properly securing the object, estimating weight, checking how deeply it's embedded in the bottom, making sure the area is clear and everybody is away from the lines, etc.).

Terry

 

[Web Monkey]

This is exactly taught in the scientific diving class. Good description!

It beats the heck out of the other method, which is to attach a liftbag, add air until the object breaks free of the bottom, then goes hurtling towards the surface, only to come unhooked, fall back down and kill you.

Terry

 

[Lil' Irish Temper]

It beats the heck out of the other method, which is to attach a liftbag, add air until the object breaks free of the bottom, then goes hurtling towards the surface, only to come unhooked, fall back down and kill you.

Terry

I just watched guys use 55 gallon drums as lift bag, you want to talk about scary. But they knew what they were doing though.

 

[Rick Murchison]

It beats the heck out of the other method, which is to attach a liftbag, add air until the object breaks free of the bottom, then goes hurtling towards the surface, only to come unhooked, fall back down and kill you.
Terry

Uh, doing it (a free lift at neutral buoyancy) right and safely takes a little practice and technique, but it ain't exactly rocket science either...
Rick

(photo credit - Tom Smedley)